The idea of reversing the momentum of a mass to achieve propulsion is not new. It has been used by Boeing aircraft for slowing down aircraft while in flight, and for both braking and moving the aircraft backwards while on the ground. It involves lowering a large structure, shaped like a cup, over the back of the jets engines. The force of gases on the structure over come the foreword acceleration of the jet engines, resulting in a reverse thrust. This type of system is an open system in which matter is spewed into the environment. A closed system is one in which no mater or energy is expelled from the propulsion system. The present invention is directed to a magnetohydrodynamic pump that is adapted for use in a closed propulsion system. In U.S. Pat. No. 5,111,087 to Butka, there is disclosed a system utilizing a magnetohydrodynamic pump in which liquid is accumulated in a duct and moved by a magnetic field to apply a thrust.
The Butka patent has the following limitations:
(a) The electrode placement is such that the current is parallel to the liquid flow. This breaks the Lorenz Force Law which states that the flow, current, and magnetic field must all three be mutually perpendicular.
(b) This system describes using water as the working fluid. The use of water is impractical because the large currents necessary for operational force would require thousands of volts. This high voltage coupled with high current will result in a tremulous amount of heat being transferred into the water. This would quickly vaporize the working fluid.
(c) Since symmetrical ducts exist at both the top and bottom of the structure, it is difficult to see how a unidirectional force is obtained. Water is a fluid and can not be compressed and since this is closed system, the velocity of the fluid should be approximately the same at both the top and bottom constricted ducts. This means the force pushing on the top duct should cancel the force pulling on the bottom duct.